Investigation of heavy metals contamination of edible marine seafood

Abstract

Levels of trace metals (Co, Cu, Fe, Mn and Zn) were determined in some marine species (Tilapia zilli,
Callinectes sapidus and Littorina litorea) collected during different seasons from Ondo coastal region,
Nigeria. Both species-dependent variability, residency of the organism and temporal variations were
pronounced. A general trend in concentration with the following in decreasing order occurred: Fe > Cu >>>
Mn > Co > Zn. An overall elevated concentration of these metals was observed during the wet season
particularly in crab and periwinkle when low pH and salinity pervaded in the aqueous medium. The highest
bioconcentration factor (BCF in brackets) for Mn (0.21) and Zn (2.33) were observed within crab while those
of Co (0.98), Cu (2.19) and Fe (9.95) were observed within periwinkles. Significant correlations (P < 0.05) were
recorded between tissue concentrations and size/length of biota. A continuous monitoring program is
recommended to establish the studied organisms as bioindicators and to identify future changes to conserve
the ‘health’ of this fragile ecosystem.